Alternating-current controller.



D. LARSON. ALTERNATING CURRENT CONTROLLER.

APPLIUATION FILED 00T.2, 1905. 1,01 1,212.

Patented Bea-12,1911.

2 SHEETS-SHEET 1.

WITNESSES.-

D. LARSON.

ALTERNATING CURRENT GONTROLLER. APPLIGATION FILED 0 1T.2, 1905.

1,011,212. Patented Dec. 12, 1911.

SHEETS-SHEET 2.

I V igeqvi W/TNES'SESJ/ d INVENTOR ATTORNEY DAVID LARSON, F YONKERS, NEWYORK.

ALTERNATING-CURRENT CONTROLLER.

Specification 0t Letters Patent.

. Patented Dec. 1 2, 1911 Application filed October 2, 1905. Serial No.280,976.

To allwhom it may concern:

Be it known that I, DAVID LARSON, a subject of the King of Sweden, and aresident of the city of Yonkers, \Vestchester county, New York, haveinvented certain new and useful Improvements in Alternating-CurrentControllers, of which the following is a specification.

My invention relates to an electro-mag netic switch or actuating devicewhich-is operated by alternating, intermittent or pulsating currents,without the vibrations or chattering which is usually present in ap- Twomagnet poles 13 13 are thus formed with the gap 13 between the faces ofthe same.

Movable between the poles 13 and 13 is a laminated armature 20, which inthis instance is shown as supported in a frame at the outer end of alever 21, preferably of non-magnetic material, such as brass. This leveris pivoted at 22 on the outer end of the bracket 30 which maybe attachedto the base board as shown at 31.

The armature may be held in its outer or initial position by gravity orby some mechanical device such as a helical spring 24. A rod 26 extendsthrough and supports this spring, and is guided at its inner endthroughthe extension 32 of the bracket and a hole in the base board 10.v The outer end of this rod is pivoted at 27 to the'lever 21. Anintermediate portion of the rod is threaded to receive the nuts 25 bywhich the position of the spring 24 may be adjusted.

same apparatus with certain electrical cir-' cuits showndiagrammatically. Fig. 4 illustrates a detail of construction. Fig. 5shows a portion of the device shown in Fig. 1, but

arranged to control a valve. Figs. 6 and 7 are side and front elevationsshowing a modification of the invention.

Like characters of reference corresponding parts-in all of the figures.

- of the laminations constitutes the core electro-magnet and the outside11, 11 and 12, 12 are bracket plates pref-.

designate erably of non-magnetic material which may be bolted rigidly tothe base or support 10 by means of bolts 115,11 and 12 12 "lhese sets ofbolts are spaced apart to permit the magnet spool 15 to fit between theplates 11, 12, and 11, 12.

The electro-magnet designated as a whole by the reference number 13,comprises the wind- .ing spool 15 and the bundle of U-shapedlaminations'88 on which the spool 15 is placed and wound with insulatedwire. the projectbeing clamped between ing or exposed portions of thelammations the plates 11, 12 and 11, 12 respectively. The coveredportion portionsthe poles which in this instance extend forwardly fromthe board 10. These extensions are preferably curved so that; their endsface each other across the space 13.

of the Connected rigidly with the lever 21 is the lower extension 28which abuts against a stop lug 33 on the bracket 30, to limit theoutward movement of the armature 20.

In Fig. 4 is shown a plan view of the braclnet 30 including its outerrectangular portion in which is pivoted the lever 21. It. is animportant feature of my invention that this lever is so pivotedas tohave minimum 'friction and be free from lateral vibrations, and still beso arranged-as to be laterally adjustable so as to bring the arma -tureinto symmetrical position with respect to the poles 13 and13. In suchevent the armature poles and the bracket 30 may be so arranged as tocompel the armature 20 to move between the poles 13 13, to a po,- sitionwhere the magnetic pull on both sides of the armature 20 will besubstantially equal, and therefore the tendency for lateral vibrationreduced. It is found, however, that the armature 20 will not always 7occup a magnetic symmetrical position and therefore it is desirable tohave the armature lever 21 laterally adjustable toa position where thehum or chattering due to unequal pulls is reduced to such an extent thatit is practically negligible.

As indicated in Fig. 4 set screws 22, 22' are screw-threaded through therectangular portion of the bracket 80" and theirinner conical ends 22fit into corresponding lateral recesses in the lever 21. Now after thescrews 22, 22 have been moved inwardly to such a position that all lostmotion is taken up and the lever 21 has been moved to such a positionthat the armature 20 will occupy a magnetically symmetrical positionbetween the poles 13 and 13, the lock nuts 22 are turned to clamp thescrews 22, 22' and the conical bearings 22 rigidly in their adjustedpositions. At 34 is pivoted in any desired manner an additional lever 40which has no direct connection with the lever 21, the swing ng arm orlever 40 is provided with an adjustable set screw 43 against which thelever 21 rests when the magnet is not energized. The position of the setscrew 43 may be adjusted so as to change the initial position of thearmature 20 with respect to the poles 13 13 A look nut 44 is providedfor holding the set screw 43 in adjusted position. A lug 45 near one endof the swinging arm 40 is provided between which and the outer portionof the bracket 30 a spring 46 may be spaced. This spring is supported ina recess 35 and its position in said recess may be varied or adjusted bythe screw 47 Above the magnet 13 is another bracket 50 attached lo thebase 10 by the bolt 51. The outer enjl of this bracket supports-acontact holder 53 the stem of which passes loosely through the bracket50. The holder 53 carries the contact 52 and is held in its outerposition by the spring 54, such outer position being limited by theadjustable nuts 55. The contact 52 is directly in the path of movementof the contact 41. carried by the upper end of the swinging arm or lever40.

The control of the levers 21 and 40 will now be described. The spring 46has sufiicient strength to move the lever 40 to its dotted line positionwhere the contact 41 engages the contact 52, provided the lever 21. ismoved to its dotted line position by the energization of the magnet. Thespring 24 is of suiiicient strength to overcome the action of the spring46 and to hold the swinging lever 40 and contact 41 in their positionsshown in full lines in Fig. 1. The weight of the armature 20 and thelever 21 may be arranged to assist the spring 24 in performing itsfunction. The relative positions of the levers 21 and 40 may be adjustedby the threaded bolt 43. This also adjusts the air gaps between thepoles 13 13 andthe armature 20. Now when the magnet 13 is energized andpulls its armature 20 between its magnet poles 13 and 13 the swingingarmature supporting lever 21 is pulled away from the swinging lever 40after contact 41 engages the contact 52. During the first motion,however, the spring 46 causes the lever 40 to follow the lever 21, butafter the contact 41 engages the contact 52 the lever 21 is given anadditional movement so as to be entirely out of mechanical contact withtthe inner end of the s rew 43 or any portion of the lever 40. Thespring 54 will cushion the blow of the contact 41 against the contact 52and said contacts will be broughtsquarely into engagement with eachother since the stem of the holder 53 extends loosel through the bracket50. It will there ore be evident that the electric switch comprising thecontacts 41 and 52 will be held closed by the spring 46 independently ofthe electro-magnet and its armature. The armature 20 and its supportinglever being entirely clear and free from the swinging lever 40 novibration from the armature can be transmitted to the lever 40 or thecontacts 41, 52. This will eliminate all chattering between the contacts41 and 52 with its attendant difficulties such as sparking and noise. When the current is cut oil from the magnet 13, the spring 24 pushes thelever 21 back against the lever 40 and the latter will therefore bemoved against the action of the spring 46 back to its initial position,thereby separating the contacts 41 and 52.

It is a well known fact that an electromagnet energized by alternatingcurrent will have a pulsating effect upon its armature due to thecurrent fluctuations, there is therefore a tendency of the magnet to vbrate the lever 21 when the magnet is energized. It will be observed,however, that 'the lever 21 is supported on anti-friction bearingswhich' are laterally adjustable. The laminations S8 and the laminationsof in this instance. Sofar as is practicable the armature is mountedsymmetrically with respect to the pole faces of the magnet, but due toirregularities of the pole faces or of the size of the armature, thelatter may not be in exactly midway position between the pole faces,magnetically speaking. The conical bearings may however be shiftedsideways so as to obtain a position for the armature where minimumhumming will be produced when the magnet is energized and the armatureis in its attracted position. It

is energized and the armature 20 brought to its dotted line position asindicated in Fig. 1, the magnetic circuit is almost entirely closedwhich materially reduces the current taken by the magnet. The spring 24should be so adjusted with respect to the pull of the magnet that thearmature 20 is not brought into contact with any portion of the magnet.In other words the armature should be brought by the pull of the magnetagainst the action of the spring 24 in a state of equilibrium where thearmature will not be permitted to touch anything and thereby producechattering noises.

In order to show the practical application of my invention I haveillustrated in Fig. 3

the armature 20 are horizontally arranged should also be noted that whenthe magnet a source of sing lephase alternating current 60 connectedthrough the transformer 61 to the conductors .63 and 64 which areconnected to the terminals of the magnet solenoid 15. A manual switch 62may be used to control the flow of current. through the magnet solenoid.To the binding postwhich is connected to the contact 41 but insulatedfrom the lever 40 by the insulating blocks 42 is connected aconductor 75leading to the incandescent lamps 74.; The other contact 52 of theelectric switch isconnected by the conductor 78 to the solenoid 70inwhich is movable a plunger 77. This solenoid is connected by theconductor 71 to the conductor marked and leads to a suitable source ofdirect currentsupply. Conductor 75 is connected to the w lead of thesaid source of direct current supply. Now when the switch 62 is closedand the alternating current generator 60 is operated the solenoid willreceive alternating current and the armature will be moved to a positionof equilibrium disconnectedfrom any portion of the magnet. Upon theinitial movement of the armature 20 the spring 46 willcause the lever 40to follow the lever21 until the contact 41 engages the contact 52.Thereupon the circuit through the solenoid 70 will be'completed and theplunger 77 will be lifted and with it the circuit closer 78 to connectthe contacts 72 and 76. The circuit will then be closed through thelamps 74 and 'the solenoid 70 will still receive current through acircuit in parallel with the circuit through the lamps. The circuits andconnections of Fig. 3 are merely for the purpose of illustration of anapplication of my invention,- it being understood th t it may have ageneral application. For i stance it may be used as. an electro-magneticswitch in electric elevator apparatus. In Fig. 5 I have shown myinvention applied to valve mechanism. Here a swinging arm or lever isconnected by a link 82 to a valve 81 which is slidable in the guideway80. This valve maybe arranged to control inlet and outlet passages 83and 84 to the inclosed chamber 85 in which is shown a piston 86 arrangedto be moved against the action of a returning spring 87.

In Figs. 6 and 7 is shown a modification of my invention in which themagnet frame 13 is circular in form with two inwardly roller 17 whichinitially rests against a lug 45 of the. swinging lever 40. .lVhen themagnet is deenergized the weighted member with its roller17 resting upona lug 45 Wlll protruding magnet poles 13 and 13"be-- tween which apivoted rotatable armature cause the armature 20' to assume the position shown in Fig. 6, where it extends diagonally from the upper portionof one pole to the lower portion of the other. The position of the lug45- and the other parts are such that ,when the roller 17 is limited inits downward movement by the said lug the armature still connects thepoles with the exception of small air flaps. It will therefore beevident that initially the magnetic circuit is almost entirely closedand still suiticient movement of the armature may be obtained to efiectthe operation of the electric switch. Now when a current is sent throughthe windings 15, 15, by closing the switch 62 as before described inconnection with Fig. 3, themagnet 13 will be energized and the armature20 will be turned about its pivot into the position indicated by dottedlines in Fig. 6 to more completely close the magnetic circuit; or inother Words, to include a maximum number of the magnetic lines of force.In so doing the roller 17 will be moved into its dotted line position17. The lever 4O will follow the roller 17 until the contact 41 engagesthe cont-act 52, after which the roller 17 will be moved entirely out ofengagement withthe lever 40". The roller 17 being entirely free andclear from the lever may havev a considerable vibration, such as thatdue to fluctuations in the exciting current without coming into contactwith the lever 40. It will be ob served that the springs 46 rotatethe,lever 40 on its pivot 22 when the weight 16 is moved to its dottedline position. The tension of the springs 46 may be independentlyadjusted by the adjusting devices 47 When the exciting current is cutoff the member 16 will move the roller 17 back to 105 its full lineposition and move the lever 40 to. its initial position against theact-ion of the springs 46. The contacts 41, 52' will thereby beseparated.

In the apparatus disclosed the vibrations of the alternating currentmagnet are entirely removed from the electric switch which it controls,and therefore chattering noises and infirm electrical connections at thecontacts are eliminated. Furthermore, since the 115 armature is firmlypivoted or mounted on anti-friction bearings, and is held fromcominginto contact with the pole pieces of the magnet when it is drawnto attracted position all other noises are also reduced to a minimum. Ihave shown my invention in two different forms and have shown it appliedto different kinds of apparatus in order to demonstrate that it is notlimited to any specific construction or to any spcific use.

My invention contemplates such modifications as come within the scope ofthe appended claims.

Having thus fullydescribed my invention, '13P what I claim and desire tohave protected by Letters Patent of the United States is:

1. The combination with an alternating current magnet comprising amagnet frame having two poles, of an armature, a pivoted membersupporting said armature and securely held against lateral movement, anadjustable spring arranged to act against said pivoted member,connections for restricting the movementof said armature to a positionof equilibrium between the pull of the magnet and the action of thespring, and an independent swinging arm situated in close proximity tosaid pivoted member but arranged to have its movement controlled by saidmember, and independent adjustable mechanism for moving said swingingarm when the armature is pulled into a state of equilibrium by themagnet.

2. The combination with an alternating current magnet, of a movablebody, an armature resting against said movable body, con nections toeffect the movement of said armature from the path of movement ofmovable body into a state of eq a" an appliance for actuatin saidmovable body when the armature is pulled away from the path ofmovementof the same, a device for adjusting said actuating appliance, andadjustable yielding abutments to limit the movement of the movable body.

3. The combination with an alternating current magnet having a laminatedframe, of an armature having laminations substantially in the same planeas the laminations of said frame when the armature is in attractedposition, means for adjusting the position of the armature with respectto the frame and an independently movable body controlled by themovement of the said armature.

4. The combination with an alternating current magnet comprising alaminated frame, of an armature having laminations substantially in thesame piane as the laminations of the frame when the armature is inattracted position, a lever for supporting the armature, conicalbearings for said lever, means for adjusting the position of saidbearings to shift the position of said lever and a movable switch arm.

5. The combination with an alternating current magnet having laminatedpole pieces, of an armature having its laminations extendingsubstantially in the same plane as the laminations of the pole pieceswhen the armature is in attracted. position,

means for adjusting said armature to a magnetically symmetrical-positionbetween said pole pieces and a movably adjustable switch arm.

6. The combination with an alternating current magnet having twolaminated pole pieces, of an armature having laminations extending inthe same direction as the lami-- nations of the poles, a lever forcarrying said armature, conical bearings to prevent lateral vibration ofsaid armature and lever. means for adjusting said bearings to shift saidlever and armature laterally until the armature occupies a magneticallysymmetrical position between the poles, a switch comprising a switcharm, controlled by the said armature and a stop to regulate the movement of the arm.

7. The combination of an alternating current magnet comprising amagnetic frame, an armature movable into and out of a position ofequilibrium between the pole faces of the magnet, a pivoted arm carryingthe garmature, and a pivoted member in the path of the armature andmovable into a position substantially parallel with said arm when thearmature is in its attracted position.

8. The combination with an alternating current magnet and its armature,of an armature lever, a pivoted member in the path of movement of thelever and substantially parallel with said lever whenthe mag net isdeenergized, but disconnected from said lever, and means for causingsaid member to follow the armature during a portion only of, thearmatures-movemcnt when the latter is moved to attracted position.

9. Theccombination with an alternating current magnet, of an armaturemovable into a position of equilibrium between the poles of the magnet,a pivoted lever carryin the armature, a switch leverin position to beheld open by the armature and having its pivot in' proximity to that ofthe armature, means for causing the switch lever to follow the armatureas the'latter moves to attracted position, and a stationary switchmember in position to intercept the switch lever before the armaturereaches its attracted position.

In testimony whereof, I have signed my name to this specification in thepresence of two subscribing witnesses.

DAVID LARSON.

Vitnesses:

JOSEPH E. GAVANAUGH, I ERNEST W. MARSHALL.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. 0.

